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ItemWhoPre-Meeting NotesNotes and  Action Items
Project/Science Updates

No PST meeting last week

Many people involved with either the DESC meeting or the Joint Operations Review this week. 

Do we want to have a meeting at the JTM?

DESC session on Wed 10:45 Pacific  for a discussion on Parallel 3.3 Survey Non-uniformity Effects. There might be a discussion on non-uniformity. 

  • SC Chairs PST meeting this week in the PST slot.  AuxTel is the topic. It will be recorded. 
  • If we have an agenda item, it might be good to have a 1-hour meeting. Stretch goals, DR1 definition.  Leanne will think about possibly topics. 


Shear measurement pipeline followup

Follow up discussion on the shear measurement pipeline in DM and discussion of a Rubin metadetect table schema and other implications for DM. 

Goal is to converge on a  conceptual schema to add to the DPDD and to prepare an RFC  

slides from the DESC presentation

has links to draft PR and PDF.

  • New section 4.2.6 describing the shear measurement approach that  was presented last week.
  • Proposing a separate ShearObject table, no matches to the Object table. 
  • Naming conventions, acronyms, camelcase .... can we do better?
  • CTS/JB: this is one column for g,r,i bands  same as  the Object table 
  • JB: Could see table growth if we want quantities per-band as well as averaged across bands.
  • JC: Are we presuming a cell table that this can be joined to?
  • JB: In the same boat as ccdVisit, tract, patch table.  Provenance table is probably the most important. Not sure if this is in the DB or in the Butler provenance system
  • LPG/CTS: Looking like this table will be ~1/4 number of columns as the Object table. 
  • JB: We can bitpack flags but this is not well supported by SQL nor Parquet. Flags dp not come for free. 
  • JC: Table name - does this only imply that it is only useful to a specific science? Can we come up with a different name that implies broader use?
  • JB: It really is only useful to WL and is not useful for the physical sizes or ellipticities of galaxies. Table goal is to present the sky as a background field that gets distorted by a foreground field, not as a table of individual astrophysical objects.
  • LPG: Need to make sure that the ShearObject table is not mistakenly used  by the community - there are columns with similar names as in the Object table. Take the same approach as for SSO tables. ShearObjects focused on a specific science case, just as SSObject tables do.  
  • CTS: Joins to a cell table are not really a worry.  Concerned about provenance tables for the images that go into cells. Would like to see a physical schema for that sooner than later.
  • CTS: Has informed DAX team about this - no one is freaked out.
  • JB: Cell provenance table does not necessarily need to be in the DB, it could be in Butler. 
  • CTS: Some people might wonder why they cannot get the all the relevant data from Qserv and have to go to Butler to get some data. Could result in a bad UX. 
  • JB: If DAX say it is OK to put into Qserv  then OK 
  • CTS: This can go ahead  without a cell table - will want an example later but not urgent
  • CTS: Rollout might be a good topic for a PST science collab chairs talk . Together with the removal of Object extra (MCMC samples) . 
  • LPG:  Make any talk to the PST / SC Chairs general to cover all recent updates to the DPDD. e.g  
    • Astrometry - DR1 goals are different to the final goals 
    • We store deblending outputs better now
    • Cell-based coadds  - discuss this more - what does this mean for firefly
  • MLG: Cell based coadds - are these a new image data products? 
  • JB: Only called out in the ShearObject table - implementation detail of how we build the coadds. This might affect how the file for cell-based coadds will look.  All Object quantities will come from the cell-based coadds.
  • MLG: Why not issue cell-based templates
  • JB: Not clear we will get any benefit and don't want to rock the boat at this stage. Possibly post DR1 but 
  • Jim Bosch Create an RFC the proposed ShearObject table (once ES has had a chance to comment)   RFC-921
  • Leanne Guy talk to Steve R about presenting plans for the ShearObject table to PST and SciCollab chairs   
  • Jim Bosch  Provide a physical example of that a  up on cell table would look like fo the Colin Slater / DAX team to review  
  • Jim Bosch Provide an example of a file containing a cell-based coadd for Gregory Dubois-Felsmann to examine to assess implications for firefly  
Proposal for wrapping up Obs package work 

DM-12676 : Obs package refactor has been lingering for a long time at low priority. I propose to try to get a software developer from the in-kin general pool to assist with completing this work


AOB

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List of SST tasks (Confluence)